Evidence of Allopolyploidy in Urochloa humidicola Based on Cytological Analysis and Genetic Linkage Mapping

Autor: Cacilda Borges do Valle, Maria Marta Pastina, Jean C. S. Santos, L. Jungmann, Antonio Augusto Franco Garcia, Maria Suely Pagliarini, B. B. Z. Vigna, Anete Pereira de Souza, Marcelo Mollinari
Jazyk: angličtina
Rok vydání: 2016
Předmět:
0106 biological sciences
0301 basic medicine
Genetic Linkage
lcsh:Medicine
01 natural sciences
Microsatellite Loci
Urochloa
Cell Cycle and Cell Division
lcsh:Science
Genetics
education.field_of_study
Multidisciplinary
biology
Chromosome Biology
Plants
Meiosis
Cell Processes
Microsatellite
Research Article
Population
Locus (genetics)
Quantitative trait locus
Research and Analysis Methods
Poaceae
Chromosomes
Polyploidy
03 medical and health sciences
Gene mapping
Gene Types
Genetic linkage
Apomixis
Grasses
Molecular Biology Techniques
Linkage Mapping
education
Molecular Biology
Metaphase
Gene Mapping
lcsh:R
Organisms
Biology and Life Sciences
Cell Biology
biology.organism_classification
030104 developmental biology
Genetic Loci
lcsh:Q
Departures from Diploidy
Microsatellite Repeats
010606 plant biology & botany
Zdroj: PLoS ONE, Vol 11, Iss 4, p e0153764 (2016)
PLoS ONE
ISSN: 1932-6203
Popis: The African species Urochloa humidicola (Rendle) Morrone & Zuloaga (syn. Brachiaria humidicola (Rendle) Schweick.) is an important perennial forage grass found throughout the tropics. This species is polyploid, ranging from tetra to nonaploid, and apomictic, which makes genetic studies challenging; therefore, the number of currently available genetic resources is limited. The genomic architecture and evolution of U. humidicola and the molecular markers linked to apomixis were investigated in a full-sib F1 population obtained by crossing the sexual accession H031 and the apomictic cultivar U. humidicola cv. BRS Tupi, both of which are hexaploid. A simple sequence repeat (SSR)-based linkage map was constructed for the species from 102 polymorphic and specific SSR markers based on simplex and double-simplex markers. The map consisted of 49 linkage groups (LGs) and had a total length of 1702.82 cM, with 89 microsatellite loci and an average map density of 10.6 cM. Eight homology groups (HGs) were formed, comprising 22 LGs, and the other LGs remained ungrouped. The locus that controls apospory (apo-locus) was mapped in LG02 and was located 19.4 cM from the locus Bh027.c.D2. In the cytological analyses of some hybrids, bi- to hexavalents at diakinesis were observed, as well as two nucleoli in some meiocytes, smaller chromosomes with preferential allocation within the first metaphase plate and asynchronous chromosome migration to the poles during anaphase. The linkage map and the meiocyte analyses confirm previous reports of hybridization and suggest an allopolyploid origin of the hexaploid U. humidicola. This is the first linkage map of an Urochloa species, and it will be useful for future quantitative trait locus (QTL) analysis after saturation of the map and for genome assembly and evolutionary studies in Urochloa spp. Moreover, the results of the apomixis mapping are consistent with previous reports and confirm the need for additional studies to search for a co-segregating marker.
Databáze: OpenAIRE
Externí odkaz: